For pressure-filling containers, it is known to use a single-chamber filling system. In such a system, the filling process includes a filling phase. The filling phase involves opening a liquid valve so that liquid filling material flows into a container that is arranged in sealed position against the filling element. This container will have been pre-tensioned with an inert gas that is maintained at filling pressure. As the container fills, the liquid filling material displaces the inert gas. This displaced gas returns, through a return gas tube that extends into the container during filling, to a gas space of a partially filled tank or into a channel carrying the inert gas. Both the tank and the channel are maintained at the filling pressure.
As the liquid fills the container, it eventually immerses the bottom of the return gas tube. The filling material rises in the return gas tube until a state of equilibrium is reached between the level of the filling material surface in the tank and an equilibrium level of the filling material surface in the return gas tube.
The liquid valve is not closed until after this state of equilibrium is reached. In a rotary filling machine, the liquid valve is not closed until the rotor has carried the filling element to a predetermined angular position. The point in time and/or angular position of the rotor at which the liquid valve finally closes are selected so that, when multiple filling elements are present, the desired fill height is reliably reached even with the slowest of these filling elements. This wait occurs even though it is in principle possible to close the liquid valves of the filling elements much earlier. This means that the total duration of the filling process is artificially extended. As a result, the throughput of the filling machine is artificially reduced.
In a known pressure-filling system, each filling element has a probe that governs the fill height in the bottle and that, during filling, extends through the bottle mouth into the bottle or into the bottle's neck or body region. At its lower end the probe forms a probe contact and is at the same time configured as a gas tube with a gas channel that is open above the probe contact by radial openings.